Varroa Management for 20 to 100 Hive Operations

The 20 to 100 hive range is where hobby beekeeping ends and the real business of beekeeping begins. Operations at this scale are usually generating some income from honey, package sales, or pollination contracts, but they are typically managed by one or two people rather than a full crew. Varroa management at this scale is more demanding than hobby beekeeping but has different constraints than large commercial operations.

What Changes at This Scale

With fewer than 20 hives, you can inspect every colony frequently and make individual decisions about each one. Above 100 hives, you are essentially running yard-level protocols and treating by the block. Between 20 and 100, you are in a middle zone where some individual management remains practical, but you also need system-level thinking to stay ahead of varroa.

The key shifts at this scale:

You cannot afford to count every hive every time. A 10% sample rule is practical and validated. Count a minimum of 10% of hives in each yard, with at least 3 hives sampled per yard, and always include any colonies that look off or have shown elevated counts previously.

Treatment decisions increasingly apply to whole yards. If your sample shows 3 of 5 counted hives above threshold in a yard, treat the whole yard. Individual treatment of specific hives in a yard is inefficient and the uncounted hives are likely to be above threshold too.

Records become operationally necessary, not optional. At 100 hives, your memory cannot reliably carry treatment dates, post-treatment counts, and PHI clearance dates for each colony. A record system is part of the management infrastructure.

Building a Monitoring Schedule

For a 50-hive operation across three yards, a realistic monitoring schedule looks like this:

• Count 5 to 6 hives per yard per monitoring visit (10 to 12% of total)
• Monitor every 4 weeks during active brood season (April through October in northern regions)
• Monitor every 6 to 8 weeks in late fall and early winter
• Count before and after every treatment event

This schedule generates roughly 50 to 60 mite count data points per season, which is a manageable workload and enough data to understand the mite situation in each yard.

Treatment Timing for Small Commercial Operations

The fall treatment window is the most critical for operations in northern climates. Getting below threshold before winter bees are raised in August and September protects the colony through winter. The spring treatment manages the rebound mite population before the main honey flow.

A typical annual cycle for a small commercial operation in the northern US:

• Mid to late August: Apivar strips in after the last super comes off. Strips stay for 6 to 8 weeks.
• Early to mid-October: Strips out, post-treatment mite count.
• December to January: OAV during natural broodless period if available, or no treatment if counts are below 0.5%.
• April to early May: Pre-flow mite count. Treat if above threshold using thymol or a rotation product. Remove treatment before supers go on.
• Mid-season check: Mite count in July or August before making the fall treatment decision.

Adjust this template for your specific climate. In the Southeast, the broodless period is not reliable and the schedule shifts accordingly. See the varroa management for the Southeast climate guide for regional adjustments.

Batch Treatment Logistics

Treating 50 hives efficiently requires pre-staging. Know what you are treating and with what before you arrive at each yard. Count the strips or measure the doses you need. Bring slightly more than you need to avoid running short in the field.

Log treatment as you go rather than after you return home. A dedicated app on your phone, with the yard and hive list already populated, lets you check off each hive as you treat it and catch any hives you might have skipped. Reviewing the list before you leave the yard takes 60 seconds and prevents the frustrating discovery back at home that one colony was missed.

VarroaVault's batch treatment entry is designed for exactly this workflow. You select the yard, choose the product, enter the date, and the treatment logs to all hives in the yard simultaneously. Individual hive exceptions can be noted separately.

Managing Pre-Harvest Intervals at Scale

Pre-harvest interval management is where small commercial operations most often make costly errors. Across multiple yards with different treatment dates, tracking when supers can go back on requires a system. One yard treated August 1 and another treated August 20 have different clearance dates. A chart on the wall of your honey house or a dashboard in your management software that shows PHI clearance status per yard is essential.

Set a reminder in your calendar or in VarroaVault for the PHI clearance date of every yard after each fall treatment. Do not rely on mental arithmetic in the field in spring.

When to Upgrade Your Protocol

If you are consistently losing more than 20% of your colonies over winter in the northern US, or if you are finding colonies with high post-treatment mite counts suggesting treatment failure, it is time to review your protocol. Common issues at this scale include treatments applied too late in fall, insufficient treatment duration, and rotation drift toward a single product.

The mite count log efficacy calculator gives you concrete data on whether your treatments are achieving their expected result, and the treatment rotation planner helps you confirm your rotation is genuinely diversified.